VFS_PREOPEN(8) System Administration tools VFS_PREOPEN(8)NAME
vfs_preopen - Hide read latencies for applications reading numbered
files
SYNOPSIS
vfs objects = preopen
DESCRIPTION
This VFS module is part of the samba(7) suite.
This module assists applications that want to read numbered files in
sequence with very strict latency requirements. One area where this
happens in video streaming applications that want to read one file per
frame.
When you use this module, a number of helper processes is started that
speculatively open files and read a number of bytes to prime the file
system cache, so that later on when the real application's request
comes along, no disk access is necessary.
This module is stackable.
OPTIONS
preopen:names = /pattern/
preopen:names specifies the file name pattern which should trigger
the preopen helpers to do their work. We assume that the files are
numbered incrementally. So if your file names are numbered
FRAME00000.frm FRAME00001.frm and so on you would list them as
preopen:names=/FRAME*.frm/
preopen:num_bytes = BYTES
Specifies the number of bytes the helpers should speculatively
read, defaults to 1.
preopen:helpers = NUM-PROCS
Number of forked helper processes, defaults to 1.
preopen:queuelen = NUM-FILES
Number of files that should be speculatively opened. Defaults to
the 10 subsequent files.
VERSION
This man page is correct for version 3.3 of the Samba suite.
AUTHOR
The original Samba software and related utilities were created by
Andrew Tridgell. Samba is now developed by the Samba Team as an Open
Source project similar to the way the Linux kernel is developed.
The PREOPEN VFS module was created with contributions from Volker
Lendecke and the developers at IBM.
Samba 4.0 10/20/2013 VFS_PREOPEN(8)
